But also, the App Store, of course. Apple is in the beginning of a mobile platform war with RIM, Palm, Google, and others, and the iPod touch is a key part of it. Getting more people exposed to the App Store, which is only available on the OS X-powered touch iPod, will boost app sales, could boost iPhone sales, and should build platform loyalty and lock-in that is important, especially as Apple's rivals improve their own app platforms. Plus, it makes the App Store user base look even bigger, which makes the platform look better to developers.

It's also plausible that the more people who get to know and love the iPod touch, the more people who may want to check out Apple's forthcoming tablet, which we think is going to to resemble a big iPod touch.

And the App Store isn't Apple's only revenue-generating store on the iPod touch: It also has an iTunes store there, which continues to get new features. Arment predicts iPhone and iPod touch owners might soon be able to download TV show rentals from their phones, too. Read Marco's full post here >